Xi'an, designated PX8-344 by the Tau'ri, is a planet in the Milky Way galaxy, and is homeworld to the Xi'an race.
History
Xi'an was under the domain of System Lord Vu. It housed the Goa'uld's palace and treasury room that contained Vu's research into the stargate's ninth chevron, the Destiny, as well as contained Vu's collection of Ancient technology.
At some point, Xi'an had become liberated from System Lord Vu's reign and retained Vu's research. This made them a target of the Lucian Alliance. Vu's research however, also became an interest to Stargate Command, who tried to aid the natives in defending Xi'an but failed, due to the Xi'an military already siding with the Alliance and making it a trap for the Tau'ri.
Some Xi'an fighters under Duizhu Cheung remained on the planet while the Tau'ri escaped, in an attempt to try to fight for its liberation once more. (SGU: "Icarus 1")